Best way to find out what you’re looking for is to check for high rated recipes with flavors you like. Here on ELR and on ATF. And then buy precisely those flavors for a recipe. If you want to know more about particular flavors (like what are best mangos or lemons or…), then Noted is right place to check (since they compare dozens of apples directly; you’d get much better info about what precise apple or mango you’re looking for, than if someone here mentions you some aromas they have or use in their recipes).
Regarding Chefs. Wait for discounts - they are throwing them out every 2-3 weeks now, so it’s well worth to wait for that extra 25-30% discount on top of already discounted flavors. I don’t know if you necessarily need to use DHL for shipping to Pakistan; ordinary Royal Mail is perfectly fine and cheap and it doesn’t take too long. Flavors are so cheap lately, that even if you miss with couple of flavors, you’ll be more than satisfied with the price paid.
If you’re looking for clones of your favorite e-liquids, then expect this will be a long ride; people are not cloning that much these days anymore, because there are so many better flavors available now and making great mixes is much easier now (it doesn’t mean there are no clones, just don’t have too high expectations). Happy mixing!